Biology 1406 // Exam 1

Choose all the components of a nuclear pore.

- A central framework - A basket-like structure on the nuclear face - A set of 8 fibers on the cytoplasmic face

Choose the components of the endoplasmic reticulum.

- A phospholipid bilayer with associated proteins - A lumen

Which polysaccharides function primarily to store energy?

- Amylopectin - Glycogen - Amylose

Choose all true statements about hypotheses.

- An accepted hypothesis may eventually be rejected as new data become available. - An accepted hypothesis is a tentative idea, meaning it may or may not be true. - When scientists accept a hypothesis, that means all the available evidence supports it.

Which of the following do not occur during a chemical reaction?

- Atoms may be created or destroyed. - The number of atoms present may increase or decrease.

How are starch and glycogen similar?

- Both are storage polysaccharides. - Both are composed of α-glucose subunits. - Both are largely insoluble in water.

Which of the following bonds are nonpolar?

- C--C - O=O - H--H - C--H

Indicate the functions of the Golgi apparatus.

- Collecting molecules to be transported through the cell - Modifying and packaging proteins - Packaging molecules into transport vesicles

Select all the locations where fully assembled ribosomes can be found in the cell.

- Cytosol - Endoplasmic reticulum

Which of the following statements about orbitals is true?

- Each orbital contains a maximum of 2 electrons. - Several different orbitals may occupy the same energy level. - Orbitals are three dimensional shapes which indicate areas where electrons are most likely to be found.

Choose the three domains into which all living things are currently classified.

- Eukarya - Archaea - Bacteria

The rough endoplasmic reticulum plays a role in sorting proteins that are destined for which of the following locations?

- Vacuoles - Lysosomes - Plasma membrane

Choose the two "partners" in a hydrogen bond between water molecules.

- an oxygen atom with a partially negative charge - a hydrogen atom with a partially positive charge

Which of the following is required by all organisms in order to maintain their non-equilibrium stable state?

A constant supply of energy

Which of the following is rich in intermediate filaments made of keratin?

A fingernail

What are the four components needed to move material along the cytoskeleton in an eukaryotic cell?

A motor protein A vesicle or organelle that is being transported A microtubule A connector molecule

Which of the following cells might have a plasmodesmata?

A plant cell

What is the difference between a polypeptide and a protein?

A protein is composed of one or more long, unbranched chains of amino acids, while a polypeptide is a single, long, unbranched chain of amino acids.

In comparing flagella and cilia, which ones are longer and found singly or in pairs?

Flagella

The cell wall of which type of cell is composed of chitin?

Fungal

Which kingdom primarily consists of multicellular eukaryotic organisms that obtain energy by externally digesting food from their environment?

Fungi

Where are the genes needed for mitochondrial function located?

Genes required for mitochondrial function are located both in the mitochondrial DNA and in the nucleus.

Which of these have their own DNA with genes that produce proteins needed for oxidative metabolism?

Mitochondria

Which organelle divides independently of the cell?

Mitochondrion

Organelles are composed of which of the following?

Molecules

Flagella provide which of the following to bacterial cells?

Motility

Which of the following characteristics of living things is not used by scientists to define life?

Movement

Identify the functions of actin filaments.

Muscle movement Enzyme and ribosome binding Pinching of the cell during division

Darwin's main contribution to biology was which of the following concepts?

Natural selection

Which cells are most affected in an individual suffering from Tay-Sachs disease?

Nerve cells

The kidney is an example of which level of biological organization?

Organ

In the hierarchy of organization, organs are grouped into larger more complex units called which of the following?

Organ systems

Microscopic structures within cells that are specialized to carry out specific functions are called which of the following?

Organelles

Which of the following is the main function of the mitochondria?

Oxidative metabolism

Which of the following atoms has the highest electronegativity?

Oxygen

Archaea cell walls lack which of the following?

Peptidoglycan

Antibiotics such as penicillin and vancomycin interfere with which of the following?

Peptidoglycan synthesis

By a proton pump in the lysosomal membrane

Peroxisome

The surface of the nucleus is bounded by two phospholipid bilayer membranes, collectively called the _______ ___________

nuclear envelope

The inner surface of the nuclear envelope is covered with a network of fibers collectively known as the

nuclear lamina.

If the nuclear envelope is observed under an electron microscope, one can see shallow depressions where the inner and outer nuclear membrane meet. These are called

nuclear pores

Ribosomal subunits are produced in a region of the nucleus, called the

nucleolus

The _________ is the region of the nucleus where intensive synthesis of ribosomal RNA takes place.

nucleolus

An atom is composed of a central ________ system , which is surrounded by an orbiting cloud of ________ atom.

nucleus, electrons

Atoms are composed of a central nucleus which is surrounded by

orbiting electrons.

A type of microbody found in eukaryotic cells is the _________, where hydrogen peroxide is produced as a by-product of the action of certain oxidative enzymes.

peroxisome

In many eukaryotic cells, vesicles called _____________ process toxic chemicals using enzymes that remove hydrogen and electrons from them.

peroxisomes

The retention of conserved characteristics in a long line of descent usually indicates that these characteristics

play a fundamental role in the biology of the organism that is not easily changed once adopted.

The term ________ refers to a single, unbranched chain of amino acids, while a(n) ________ is composed of one or more polypeptide chains that are coiled and folded into a specific 3-D shape.

polypeptide, protein

Molecules move in and out of the nucleus through structures called nuclear

pores

Nuclear _________ form at the points where the inner and outer nuclear membranes meet.

pores

The________ plant cell wall is laid down when the plant cell is still growing.

primary

Cells recycle old proteins in large, cylindrical complexes called ________. In contrast to most organelles, these complexes are not membrane bound.

proteasomes

Ribosomes are responsible for ________ synthesis in the cell.

protein

The cytoskeleton is made up constantly assembling and disassembling long fibers made of

proteins

The number of ________ in an atom determines the atom's atomic number.

protons

Atomic number refers to the number of

protons.

A ribosome consists of a large and small subunit, each made of

RNA and proteins.

Which of the following may occur during a chemical reaction?

- Existing chemical bonds are broken. - New types of molecules are formed. - Atoms are transferred from one molecule to another. - New chemical bonds are formed.

Organisms that may have cell walls composed of cellulose or chitin include which of the following?

- Fungi - Protists - Plants

In water, phospholipid molecules spontaneously form bilayers. Which of the following would be located in the interior of the bilayer?

- Hydrophobic regions - Fatty acid tails - Nonpolar regions

Which of the following cells have extensive smooth ER?

- Intestine - Brain - Testes - Liver

Select all the characteristics of cellulose.

- It is the main component of plant cell walls. - It forms long fibers that are strong and resistant to digestion by most animals. - It is composed of β-glucose subunits.

Which of the following properties of living things are also properties of some nonliving things, and therefore are not used by scientists to define life?

- Movement - Respond to stimulation - Complexity

Which of the following are correctly matched?

- MreB:actin-like proteins in prokaryotes - FtsZ:tubulin-like proteins in prokaryotes

Population size for most species remains fairly constant year after year due to which of the following (choose all that apply)?

- Only a limited number of offspring survive and reproduce - Death limits population numbers

During the past 2 years, you had 4 colds while your roommate had none. During the same period, your roommate took a daily multivitamin pill while you took no multivitamin pills. Based only on these observations, which of the following would be valid hypotheses (choose all that apply).

- People who take a daily multivitamin do not get colds. - Taking a daily multivitamin reduces the chance of getting a cold.

Microbodies are found in which of the following cells?

- Plant - Fungi - Animal

Which of the following are eukaryotic kingdoms?

- Plantae - Animalia - Fungi

Water molecules are attracted to which of the following (choose all that are correct)?

- Polar molecules - Ions - Other water molecules - Substances that bear an electrical charge

Which of the following are similarities between mitochondria and chloroplasts?

- Presence of DNA - Presence of protein synthesizing ribosomes

The functions of the rough endoplasmic reticulum include which of the following?

- Protein sorting - Glycoprotein synthesis - Protein synthesis

Lysosomes contain enzymes which are able to break down which of the following?

- Proteins - Carbohydrates - Nucleic acids - Lipids

Which of the following types of molecules are typically transported through nuclear pores?

- Proteins - RNA

Which of the following are functions of lysosomes?

- Recycling of building blocks to make new molecules - Breaking down macromolecules in the cell - Digestion of substances taken in by endocytosis

How does molecular biology provide evidence to support evolution?

- Similarities in protein structure reflect how closely related different organisms are. - The sequencing of genes allows scientists to compare and trace genetic similarities among different groups of organisms.

Which of the following are limits of reductionism when applied to living systems?

- Sometimes the interactions of many parts lead to emergent properties that cannot be predicted from the properties of the individual parts. - Sometimes the components of a living system act differently in isolation than they do in their normal context.

Which of the following are examples of homologous structures?

- The wing of a bird and the wing of a bat - The wing of a bird and the front flipper of a whale - The wing of a bird and the front leg of a frog

Which of the following are examples of analogous structures?

- The wing of a bird and the wing of an insect - The eye of a human and the eye of a housefly

Which of the following are accurate statements concerning bacterial flagella?

- There may be one or more per bacterial cell. - Their movement is powered by a proton gradient

Choose all correct statements about proteasomes in eukaryotic cells.

- They are cylindrical. - They are not bound by a membrane. - They recycle old or misfolded proteins.

Which of the following are some possible harmful effects of radioactive isotopes in cells?

- They can lead to cell death in high doses. - They can produce genetic mutations.

Choose the true statements about hydrogen bonds.

- They can occur between two parts of a large molecule. - They can occur in any case when hydrogen is bound to a more electronegative atom.

Which of the following are features of actin filaments?

- They can spontaneously form in a test tube, if actin is present. - They exhibit polarity. - They are composed of two protein chains loosely twined together.

Which of the following are descriptive of energy levels?

- They indicate the amount of potential energy an electron contains. - They are often drawn as circles around the nucleus. - They consist of one or more orbitals. - They indicate an electron's relative distance from the nucleus.

Models are useful in biological research for which of the following reasons?

- They provide a way to organize how we think about a problem. - They may suggest experiments that can be performed to refine or test the model. - They can help us see the larger picture by showing how the different components of a complex system fit together.

Which of the following are examples of the limits of reductionism when applied to living systems?

- Understanding the physiology of a single Canada goose would not lead to predictions about flocking behavior. - Understanding the structure of DNA would not lead to predictions about the principles of DNA replication.

According to the pH scale shown, seawater is _______ acidic than household ammonia.

1,000 times more

Click and drag on elements in order Arrange the steps of protein transport through the endomembrane system into the correct order (start at the top).

1.transport vesicles 2.proteins are modified 3.proteins are packaged 4. proteins are released

You make two solutions: 100 mM of the very strong hydrochloric acid (HCl) and 100 mM of the weak carbonic acid (H2CO3). Which solution will have a lower pH?

100 mM HCl because it is a stronger acid.

According to the pH scale shown, tomatoes are _______ acidic than urine.

100 times more

An ion with an overall charge of +1 has an atomic number of 11 and an atomic mass of 23. This atom has ________ protons, ________neutrons, and ________ electrons.

11, 12, 10

An ion with an overall charge of +1 has an atomic number of 11 and an atomic mass of 23. This atom has ________ protons, ________ neutrons, and ________ electrons.

11,12,10

An atom has 11 protons, 12 neutrons, and 10 electrons. This atom has an atomic number of ______, an atomic mass of ______, and an overall charge of ______.

11; 23; +1

In a double covalent bond, how many total electrons are shared (please only enter the number of shared electrons)?

4

An electrically neutral atom has an atomic number of 6 and an atomic mass of 14. This atom has ________ protons, ________ neutrons, and ________ electrons.

6, 8, 6

An atom has 8 protons, 9 neutrons, and 8 electrons. This atom has an atomic number of ______, an atomic mass of ______, and an overall charge of ______.

8; 17; 0

Motor proteins that transport vesicles along microtubules require energy in the form of

ATP

The digestive enzymes in the lysosomes are optimally active at which of the following pH ranges?

Acidic

During the contraction of muscle cells, which fiber is used?

Actin

Which fiber is involved with cellular crawling?

Actin

Identify the fibers which are used in the cell division of animal cells.

Actin Microtubules

The interaction of which two proteins allows cells to crawl?

Actin and myosin

Which of the following structures are involved in cell movement?

Actin filaments Microtubules

Some bacteria produce capsules. One of the main functions of capsules is to do which of the following?

Aid in attachment

You examine 30 adult house flies and observe that each one has 6 legs. Based on these observations alone, which of the following would be a scientific hypothesis constructed using inductive reasoning?

All adult house flies have 6 legs.

You look at 50 human cells that come from different tissue types and observe that each one contains DNA. Based on these observations alone, which of the following would be a valid hypothesis?

All human cells contain DNA.

Vesicles are found in which of the following types of cells?

Animal Plant

Which of the following statements accurately describes the environments inhabited by archaea?

Archaea can be found in any type of environments.

Which of the following statements exemplifies Lamarck's theory of inheritance of acquired characteristics.

As a dolphin dives deeper, his lung capacity increases. Its offspring will then also have an increased lung capacity.

In humans, how is glucose transported in the blood?

As a simple monosaccharide

Ions play an important role in living systems in which of the following arrangements?

As individual ions

Why is solid water less dense than liquid water?

As the movement of water molecules slows down when liquid water changes to ice, hydrogen bonds form that space the molecules relatively far apart.

Which of the following is the smallest unit of an element that has all of the properties of that element?

Atom

The microtubules in a eukaryotic flagellum are derived from a(n)

BASAL, BODY

You are interested in the effect of an antibiotic on the growth of a bacterium. You set up four 400 ml beakers each containing 150 ml of medium and 10,000 cells of the bacterium. Beakers A, B, and C receive 100, 200, and 300 mg of the antibiotic. Beaker D receives no antibiotic. Bacteria are allowed to grow and their numbers are recorded at regular intervals. Which beaker is the control?

Beaker D

Why do we say that all living things exhibit heredity?

Because in all living things, DNA is copied from one generation to the next.

Why is the organic substance C2H5OH considered a compound?

Because it contains molecules made of atoms of different elements

Eukaryotic cells are much more complex than prokaryotic cells. What is the main reason for that?

Because metabolic processes in eukaryotic cells are compartmentalized.

When an acid is added to the blood, how does the carbonic acid/bicarbonate buffer work to stabilize pH?

Bicarbonate removes H+ from the blood.

How are the flagella of bacteria powered?

By a gradient of protons

After fusing with a food vesicle, the enzymes in a lysosome are activated by lowering the pH. How is that achieved?

By a proton pump in the lysosomal membrane

Which type of cell movement is involved in inflammation, clotting, wound healing, and the spread of cancer?

Crawling

What enzyme breaks down hydrogen peroxide to harmless substances in peroxisomes?

Catalase

When certain bacteria are exposed to penicillin, which of the following structures are compromised?

Cell wall

Actin fibers are involved with which type of movement?

Cellular crawling

Which structure is involved in eukaryotic cell division?

Centrosome

Which of the following are types of plastids?

Chloroplasts Amyloplasts Leucoplasts

The genes encoding rRNAs are clustered on which of the following?

Chromosomes

__________ are composed of microtubules, but are typically shorter than flagella and tend to cover all or part of the surface of a cell.

Cilia

Which of these is a hallmark of eukaryotic cells?

Compartmentalization

Constant assembly and disassembly is characteristic of which of the following?

Cytoskeleton

Which part of the cell's primary function is to support cell shape and anchor organelles to fixed locations?

Cytoskeleton

The information stored within the nucleotides of ________ molecules is used to direct the synthesis of cellular components.

DNA

Based on the general principle that ice is less dense than water, a student predicts that if he drops an ice cube into a glass of water, the ice cube will float. What type of reasoning did he use?

Deductive

As a general principle, monocots have flower parts in groups of three. An apple blossom has five petals (a petal is a part of the flower). Based on this, we can conclude that an apple tree is not a monocot. The previous statements illustrate which of the following?

Deductive reasoning

The information stored in DNA is used to do which of the following?

Direct the synthesis of cellular components

How does the presence of double bonds influence the hydrocarbon chain in a fatty acid?

Double bonds introduce kinks in the otherwise linear structure of the hydrocarbon chain.

How does artificial selection differ from natural selection?

During artificial selection, humans determine which individuals reproduce and pass on their traits.

Fibronectin binds to which of the following?

ECM Glycoproteins Integrins

Which of the following are proteins embedded within the proteoglycans forming a protective layer over the surface of animal cells?

Elastin Collagen

As complex structures are assembled from simpler subunits, which of the following may develop?

Emergent properties

What term describes a relationship, in which a smaller cell lives inside a larger cell?

Endosymbiosis

Of the three domains of life, which two are more closely related to each other than to the third one?

Eukaryotes and Archaea are more closely related to each other then they are to Bacteria.

Which of the following ideas existed prior to Charles Darwin?

Evolution

Which structure forms a protective layer rich in glycoproteins on the surface of animal cells?

Extracellular matrix

True or false: All radioactive isotopes decay at the same rate.

FALSE

True or false: A hypothesis can be proven correct if it is tested enough times.

False

True or false: If the results of several experiments agree with your prediction, you can conclude that your hypothesis is definitely correct.

False

True or false: The genome is a collection of all the proteins in a cell.

False

Peroxisomes contain enzymes involved in the oxidation of which of the following?

Fatty acids

_________ is a glycoprotein used to attach the extracellular matrix of some cells to the plasma membrane.

Fibronectin

Glycolipids

Glycolipids

The extracellular matrix is made primarily of which of the following?

Glycoproteins

Which organelle consists of a stack of flattened membranes, often interconnected with one another?

Golgi apparatus

Select the polar molecule.

H2O

Cells that carry out extensive lipid synthesis have abundant SER. Which of these cell do not have abundant smooth ER?

Heart cells

Cells that carry out extensive lipid synthesis have abundant SER. Which of these cells do not have abundant smooth ER?

Heart cells

The biological world can be viewed as organized into many different levels from the simplest to the complex, with each level composed of units from the level below it. What is the term used to describe this type of organization?

Hierarchical

Why do cells increase the production of many chaperone proteins when they are exposed to high temperatures?

High temperatures cause proteins to unfold and more chaperones are needed to help them refold correctly.

Structures that have a common evolutionary origin are called which of the following?

Homologous

Genes encoding ribosomal RNAs are often clustered together on the chromosome, facilitating the construction of ribosomes. Typically, how many copies of those genes are found on the chromosome?

Hundreds

Consider a large protein molecule that has some parts that are highly hydrophobic. When placed in a water solution, the protein folds in a globular shape, such that all the hydrophobic portions are inside the molecules, away from water. This is an example of which of the following?

Hydrophobic exclusion

Where are lipid droplets found?

In animal, plant, fungal, and some bacterial cells

Where were archaea originally discovered?

In many extreme environments, such as hot springs, acid pools, very saline waters

Within an atom, where are electrons found?

In orbitals that surround the nucleus

Integrins are proteins in the plasma membrane that extend into the cytoplasm, attaching to which two types of filaments?

Intermediate Microfilaments

Keratin and vimentin contain which of the following?

Intermediate fibers

Which of the following structures prevents excessive stretching of cells?

Intermediate filaments

Which of these cytoskeletal elements are stable and usually do not break down?

Intermediate filaments

How are ions formed?

Ions are formed when atoms lose or gain one or more electrons.

Which of the following accurately describes the major function of the nucleus?

It houses most of the DNA in a eukaryotic cell

What does it mean when we say water is adhesive?

It is attracted to other polar molecules and ions.

How is the positioning of the smooth ER related to the rough ER?

It is continuous with it.

What is the highest taxonomic level in the Linnaean system?

Kingdom

Who was the first scientists to propose the theory of evolution?

Lamarck

Which organelle is responsible for breaking down old organelles and recycling their components?

Lysosomes

Which type of RNA carries information for the synthesis of a protein that was copied from DNA?

Messenger

One of the principal ways animal and plant cells organize their metabolism is by distributing enzymes in which of the following structures?

Microbodies

Which of the following are cytoskeletal fibers that are in a constant state of flux and have a short half life.

Microtubules

Which of the following is the largest of the cytoskeletal elements?

Microtubules

_______ are long, hollow, cylindrical structures about 25 nm in diameter and composed of the protein tubulin.

Microtubules

The production of ATP is performed by which of the following organelles?

Mitochondria

Which of the following is an example of the organ system level of biological organization?

Nervous system

Choose all that are found in the 9+2 structure of a eukaryotic flagellum.

Nine paired microtubules with dynein arms Two microtubules at the core

Which of the following describes the microtubule arrangement in the basal body of a eukaryotic flagellum?

Nine triplets of microtubules connected by short protein fragments

In a molecule of hydrogen (H2), what type of bond holds the two hydrogen atoms together?

Nonpolar covalent

Why does water tends to exclude nonpolar molecules?

Nonpolar molecules disrupt the hydrogen bonds between water molecules.

The repository of the genetic information that enables the synthesis of nearly all proteins in a living eukaryotic cell is which of the following structures?

Nucleus

Terrestrial multicellular organisms that carry out photosynthesis are classified in the kingdom

Plantae

Which of the following junction types is only found in plants?

Plasmodesmata

A group of organisms of the same species living in the same place is which of the following?

Population

According to Malthus's "An Essay on the Principle of Population," how does the growth of populations of living organisms compare to the ability of humans to increase their food supply?

Populations grow geometrically, while food supply grows arithmetically.

Cells sense their environment through which of the following structures in the plasma membrane?

Proteins

The cytoskeleton of eukaryotic cells is composed of which component?

Proteins

Identify the functions of intermediate filaments.

Providing structural stability Major component in structures such as hair and fingernails

Which of the following are synthesized in the nucleolus?

Ribosomal RNA

The production of proteins is achieved by which of the following structures?

Ribosomes

The rough ER is so named due to the presence of which structures on the surface of the membrane?

Ribosomes

Which of the following would be an example of descriptive science?

Sequencing the human genome

Which of the following organelles in liver cells produces enzymes that detoxify harmful organic molecules?

Smooth ER

According to the theory of natural selection which of the following is true?

Some members of a population are more likely to survive and reproduce than others

Which of the following best describes the principle of evolutionary conservation?

Some traits change very little, if at all, over long periods of evolutionary history.

What is the fluid matrix surrounding the thylakoid membrane of the chloroplast called?

Stroma

________ biologists may build models of the structure of lipids to demonstrate the organization of lipids in a cell membrane.

Structural

What is the main downside to using radioactive isotopes to label molecules within living cells?

Subatomic particles emitted by unstable isotopes may damage living cells.

During photosynthesis, chloroplasts capture light energy and synthesize

Sugars

The approach biologists can take that focuses on the properties and functions of complex systems as a whole as well as the individual parts is which of the following?

Systems biology

Which cellular organelle functions as the "post office" of a cell, being responsible for the collection, packaging and distribution of molecules such as proteins?

The Golgi apparatus

The tertiary structure of a protein is determined primarily by interactions involving which of the following?

The R groups of the amino acids

The mitochondrial matrix refers to which of the following regions?

The compartment inside of the inner membrane

If the results of your experiment agree with your prediction, you should conclude which of the following

The evidence collected supports your hypothesis

Which of the following is an example of how comparative anatomy provides evidence to support evolution?

The forelimbs of many vertebrates are all constructed from the same basic array of bones, modified for different purposes.

Which of the following is an example of a scientific hypothesis?

The genetic information of all living organisms is stored in DNA.

Which of the following is an example of an emergent property?

The human heart pumps blood throughout the body.

How can some organisms derive energy from cellulose even though they cannot produce the enzymes needed to digest it?

The necessary enzymes are produced by bacteria and protists that live in their digestive tract.

Even though they lack organelles, prokaryotes can perform many of the functions performed by organelles in eukaryotic cells., for example, photosynthesis. Where are those functions performed?

The plasma membrane

Which of the following best describes a contemporary model of electron movement within atoms?

The position of an individual electron can't be pinpointed, however, it is most likely to be found in an orbital around the nucleus.

Choose the characteristics that are shared by all lipids?

They are nonpolar (or mostly nonpolar). They are hydrophobic.

Which of the following accurately describes bacteria?

They grow (increase in size) and reproduce by splitting in two.

If two atoms belong to the same element, which of the following must be true?

They must have the same number of protons.

How do cells mark old, misfolded, or damaged proteins for degradation by the proteasome?

They tag them with ubiquitin.

Which of the following describes the structure of DNA inside of the cell's nucleus?

Tightly wound around proteins and packaged into compact units called chromosomes

The role of the nucleolus is which of the following?

To assemble ribosomes

Which of the following is the purpose of experiments?

To eliminate one or more alternative hypotheses

How does the fossil record provide evidence to support evolution?

Transitional forms, which have a combination of characteristics from different existing groups, have been found at the predicted positions in time.

True or false: A particular enzyme usually recognizes only a single specific stereoisomer.

True

True or false: Hydrophobic exclusion affects the overall shape of many biological molecules as well as how they interact and fit together.

True

The nuclear envelope is composed of which of the following?

Two phospholipid bilayer membranes

Which of the following structures prevents excessive stretching of cells?What type of motion characterizes a eukaryotic flagellum?

Undulating

Which of these terms cannot be used to describe plants?

Unicellular

Which of the following is an example of how molecular biology provides evidence to support evolution?

Vertebrates that are more distantly related to humans have a greater number of amino acid differences in their hemoglobin polypeptide.

When non-polar molecules are placed in water, they tend to clump, thus minimizing the disruption of hydrogen bonds between water molecules. Which of the following does that explain?

Water excludes non-polar molecules.

How is the arrangement of water molecules related to its density?

Water molecules in ice are locked into a crystal-like lattice due to hydrogen bonds, making ice less dense than liquid.

Which of the following cells exhibit a crawling behavior when destroying pathogens?

White blood cells

A sodium atom that has lost an electron and has an overall positive charge is an example of

a cation.

The bacterial group Mollicutes is notable because its members, the mycoplasmas, lack

a cell wall.

Eukaryotic microtubules are very dynamic structures that have relatively short half-lives. They are typically formed at a nucleation center and have

a plus (+) end (away from nucleation center) and a minus end (toward the nucleation center)

The attraction of water to other polar substances is called

adhesion

According to the fossil record life began on Earth approximately

about 3.5 billion years ago.

According to Lamarck's theory of inheritance of ________ ________, the structures and functions of organisms are modified based on their use and those modifications are then passed on to the offspring.

acquired, characteristics

Rapid polymerization and repolymerization of _________ filaments allows the formation of a leading edge during cellular crawling. Once the leading edge is stabilized by microtubules, __________ motors pull the contents of the cell towards the newly extended front edge.

actin, myosin

A chlorine atom that has gained an electron and has an overall negative charge is an example of

an anion.

Structures that have an independent evolutionary origin but similar appearance and function are called ________ structures.

analogous

Atoms with fewer protons than electrons have a net negative charge and are known as ________, whereas atoms with more protons than electrons have a net positive charge and are known as ________.

anions, cations

If two atoms have the same number of protons in their nucleus, you can conclude for sure that they

are atoms of the same element

Some bacteria produce a thick, gelatinous layer called a(n) _________, which aids in attachment and prevent their destruction by the host immune system.

bacterial capsule

A ________ , which is the simplest unit of life, is surrounded by a membrane and contains complex biological molecules called macromolecules.

cell

The ________ ________ of a bacterium helps the organism maintain its shape and prevents the excessive loss of water.

cell wall

Bacteria, plants and animals are composed of one or more

cells

The cell walls of plants are composed of a cabohydrate polymer called

cellulose

Within the centrosome, there is a pair of structures arranged perpendicular to each other called the

centrioles

In most animal cells, the centrioles are located within a single structure located near the nuclear membranes called the _______ or microtubule-organizing center.

centrosome

Which organelles capture light energy and synthesize organic molecules, such as glucose, in the process of photosynthesis?

chloroplasts

The complex of DNA and proteins in a eukaryotic cell is called

chromatin

The association of DNA and proteins in a non-dividing eukaryotic cell is referred to as

chromatin.

Inside the nucleus of eukaryotic cell, DNA molecules are wound around proteins and packaged into relatively compact units called

chromosomes

The ________ face of the Golgi apparatus is located near the endoplasmic reticulum.

cis

Proteins transported through the endomembrane system of a eukaryotic cell usually enter the Golgi apparatus through its _______ face and exit it through the ______ face

cis, trans

The region of the cell enclosed by the endoplasmic reticulum is known as the _____________ space, or lumen.

cisternal

The fibrous protein ________ , found in the extracellular matrix of animal cells is also a major component of cartilage and tendons.

collagen

An assemblage of populations of different species that live together in one place is called a biological

community

Eukaryotic cells have an extensive endomembrane system that weaves through the interior of the cell and by numerous organelles; this allows eukaryotic cells to _____________ their biochemical reactions.

compartmentalize

In a typical eukaryotic cell, ribosomes can be found either free in the _____________ or associated with the ___________ ______________.

cytoplasm, endoplasmic reticulum

The ___________ is a network of protein fibers in the cytoplasm of eukaryotic cells involved in supporting the shape of the cell and anchoring organelles to fixed locations.

cytoskeleton

The internal scaffolding of eukaryotic cells is termed the _____________.

cytoskeleton

Carbon-12, carbon-13, and carbon-14 are

different isotopes of the same element.

Biologists have categorized all living organisms into three distinct groups based on their shared evolutionary history: Bacteria, Archaea, and Eukarya. These three groups are called

domains

Water molecules are attracted to any substance that has a(n) ________ charge, whether it be full (such as an ion), or partial (such as a polar molecule).

electric

If an atom gains or loses a(n) ________, it acquires a net electrical charge.

electron

As we look at more and more complex biological systems, we can see that they have novel properties, which result from the way in which their components interact. These novel properties cannot be easily deduced from the nature of the components themselves, and are called

emergent properties.

Scientists have proposed that chloroplasts and mitochondria arose by a process called _______, in which a smaller cell comes to live inside a larger cell.

endosymbiosis

True or false: In living systems, ionic compounds generally exist as ionic crystals.

false

The long, threadlike structures protruding from the surface of prokaryotic cells that are used for locomotion are called

flagella.

Within eukaryotes (NOT including protists), scientists recognize three kingdoms: ________ , plants, and ________ .

fungi, animalia

The collection of all the genetic material (the DNA) in a cell or organism is called the

genome

The flattened sacks of membrane typical of the Golgi apparatus are especially abundant in

glandular cells.

Non-cellulose polysaccharides that form part of the cell wall of plants are synthesized in the

golgi apparatus

Because energy transformations in living things are not perfectly efficient, all living things lose some en energy in the form of

heat

Many chaperone proteins are ________ ________ proteins that are produced in great amounts when cells are exposed to elevated temperatures.

heat shock

The stronger an acid is, the ______ its concentration of hydrogen ions and the ______ its pH.

higher; lower

Substances that attract water are called ________ ("water-loving") while substances that repel water are called ________ ("water-fearing").

hydrophilic, hydrophobic

A protein is initially driven into its tertiary structure by ________ ________ of nonpolar groups from water.

hydrophobic exclusion

A(n) ________ , is a tentative explanation that accounts for observations made by scientists.

hypothesis

The function of cell surface proteins is to give cells their __________ by marking the surface of the cell so it can be identified as being of a particular type. In multicellular organisms this allows the recognition of self versus foreign.

identity

A student examines 255 individual butterflies that belong to 73 different species and observes that each one has 4 wings. Using ________ , reasoning, and based on these observations, she hypothesizes that all butterflies have 4 wings.

inductive

Proteins called ______ link the ECM to the cytoskeleton of a cell. In addition, they can coordinate the behavior of all cells in a particular tissue by altering gene expression and cell migration patterns.

integrins

The space between the two membranes of a mitochondrion is known as the ______ space

intermembrane

In contrast to bacterial and eukaryotic membranes, archaeal membranes are built on a framework of glycerol-1-phosphate linked to ________ chains by ___________ linkages

isoprenoid, ether

Why is an atom electrically neutral?

it has equal numbers of protons and electrons

The motor protein _______ transports vesicles towards the plus end of a microtubule, while the protein ________ moves vesicles towards the minus end of a microtubule.

kinesin, dynein

The nuclear lamina covers the inner surface of the nuclear envelope and is made of a network of fibers called the nuclear

lamins

Solid water is ________ dense than liquid water.

less

In plants, DNA-containing organelles that lack pigment and a complex internal structure are called _______ When they store starch (for example, in a root cell), they are also known as _____.

leucoplasts, amyloplasts

Many cells (including eukaryotes and bacteria) contain distinct structures made of a core of neutral lipids surrounded by a lipid monolayer. These structures are known as

lipid droplets.

Tay Sachs disease is referred to as a(n) __________ storage disorder caused by a lack of function of a single enzyme necessary to break down a glycolipid.

lysosome

Centrosomes, also called _________-organizing centers, are important for cell division in animals.

microtubule

The ______ are cellular organelles, which use chemical energy stored within the covalent bonds of organic molecules to produce ATP.

mitochondria

The organelles that are both surrounded by a double membrane, have their own DNA, are involved in energy metabolism, and have their own protein synthesis machinery are the _______ and _________

mitochondria, chloroplasts

In many archaean cells, the hydrocarbon chains of membrane lipids are lined to glycerol on both ends. As a result their membranes are actually

monolayers.

Even though mitochondria divide independently from the cell, they cannot be grown in cell-free culture because

most of the components required for their division are encoded in the nuclear DNA.

Kinesin and dynein are examples of ______.

motor proteins

What type of bond forms between 2 identical atoms?

nonpolar covalent

Initially, scientists visualized electrons moving in clearly defined circular ________; however we know now that electrons travel within regions surrounding the nucleus where the probability of finding that electron is high. These regions are called electron ________.

orbits, orbital

A(n) ________ is a grouping of tissues that forms a distinct structure (for example, a plant leaf) that performs a specialized task.

organ

Most bacterial cells are encased by a strong cell wall composed of _________ , which is a carbohydrate matrix cross-linked by polypeptides.

peptidoglycan

Photosynthetic organisms use the energy in light to

reduce CO2 and produce organic compounds.

The study of individual parts of a complex system, as opposed to the system as a whole, is called

reductionism

Under the electron microscope, the rough ER appears as flattened sacs covered with bumps. Those bumps are actually

ribosomes

On its nuclear surface, a nuclear pore has a complex structure that forms a basket beneath a central

ring

Functions that include glycoprotein production and protein sorting are characteristic of the _________ endoplasmic reticulum.

rough

Patterns of coiling or folding within a polypeptide chain that are due to hydrogen bonding between the peptide groups of the main chain are referred to as

secondary structure.

Compared to carbon, the electronegativity of hydrogen is

slightly lower.

Functions that include steroid synthesis and assembly of membrane lipids are characteristic of the ___________ endoplasmic reticulum

smooth

Ca2+ ions are stored in the ______ endoplasmic ____________.

smooth, reticulum

All populations of a particular kind of organism together form a(n) _________, its members are similar in appearance and able to interbreed.

species

Actin assembly results in a fiber composed of two strands of actin monomers that ______ each other.

spiral around

The most common alteration made in the Golgi body is addition or modification of short ______ chains.

sugar

In a neutral atom, the number of electrons is equal to

the number of protons.

According to Darwin, the 14 species of finches on the Galapagos Islands resemble each other and the finches along the coast of the South American mainland because

they are descended from a relatively recent (several million years) common ancestor.

Each granum of a chloroplast contains a few to several dozen

thylakoids

The _________ stack to produce grana in chloroplasts.

thylakoids

The plant central vacuole is surrounded by a membrane known as the

tonoplast

The back of the Golgi apparatus, where materials exit, is referred to as the ________ face

trans

Which type of RNA carries amino acids?

transfer

How many subunits make up a ribosome?

two

When a protein is no longer needed by the cell, it can be tagged for degradation by the addition of a 76 amino-acid protein called

ubiquitin

The central _____ and the its membrane, the _________ are involved in maintaining the tonicity of plant cells.

vacuole, tonoplast

In contrast to other types of eukaryotic cells, many plant cells have a central ____________ which stores water.

vacuoles

In order to transport materials along microtubules, eukaryotic cells need four components: a ___________ or an organelle that will be transported, a ________ protein that uses energy from ATP to provide motion, a connector molecule, and microtubules along which the transport will occur.

vesicle, motor

Small sacs that store and transport a variety of materials are called

vesicles

Peroxisomes contain the enzyme catalase that breaks down hydrogen peroxide into oxygen and

water